Marine growth (MG) refers to the colonisation of aquatic life on the underwater surface of artificial structures. The existence of MG alters the surface conditions of structures and influences their hydrodynamic properties. In the present study, the MG was mimicked by using the 3D printed hemispherical roughness. Four different roughness heights, namely, 5%, 10%, 15%, and 20% times the diameter of the bare cylinder, were selected and the tests were conducted in a water flume using particle image velocimetry (PIV). It was found that with the increase of roughness height, the Strouhal number decreases and the boundary layers on both sides of the cylinder become thicker and move outwards. The results also indicate that the surface roughness disturbs the shear layers on both sides of the cylinder which then influences the vortex shedding frequency and the wake formation length.
|22nd Australasian Fluid Mechanics Conference, AFMC 2020
| 22nd Australasian Fluid Mechanics Conference
|7/12/20 → 10/12/20